Converting to 1x9 or even 1x5?

I bought my Diamondback Overdrive 29er last Friday, and took it out every day since then (today was the 5th day of ownership, and thus the 4th ride), averaging probably an hour per trip through about 5 miles of somewhat technical trails. After the first day, I found myself not using the front derailleur just because it seems to shift rougher, and have begun to discover that I can do everything I need to on just the middle gear of the front set, and about the largest 4 gears on the rear cassette. I find that my best climbing so far has been done with the front deraileur on the middle sprocket and the rear on the lowest one, and I can climb to the limits of traction or balance (wheelie or lose traction). I generally seem to stay on 2nd gear on both ends, and only on the flat gravel roads between trails have I gone to 3rd or even 4th gear.

So, I was thinking I might be able to save some weight and gain some subjectively-romantic simplicity by going to perhaps a 1x5 setup? I would likely start with 1x9 just because it would be relative easiest, and because at least for a while I don't know if I'd ever be interested in riding street again (commuted on a cross-comfort for a few years).

I've been preaching 1x9 for several years now. There's really good 1x9 thread over at MTBR that I've been pretty active in. Terrain dictates though. I was 1x9 and 2:1 SS in my old town...and there was actually more climbing there than here. The reason I switched back is b/c the terrain is more technical so I have to pick my way through some sections that a 1x9 was a little too tall to handle.

1x5...why? You're not going to save any noticeable weight by dumping 4cogs off the bottom of your cassette. I've never understood why someone would do that. If you have to have the shifter, derailleur, cables, and cassette...just put the other 4 gears on there. You will probably run into a trail or street / urban ride one day that you would spin out of w/o them.

You will easily drop your chain on rough terrain with a 1x9 setup if you don't have any way to keep it on there. The best way to do it w/o the extra weight and noise of a guide is to use an outer and inner bash setup giving you a "chain sandwich". BBG and Blackspire both make really nice inner rings that are the same size as your bash ring. Run whatever bash you like and bolt the BBG inner ring or Blackspire Blackguard on the granny spot. This will keep the chain on better than any of these goofy little gadgets you see people running except for full-on DH / FR chain guides.

You can save some weight losing a shifter, derailleur, cable...but the really nice thing about it is just simplicity. Before you know it, you'll be running a singlespeed.

So I could get the product on the top left (the 104 BCD "4-11/16 OD Trials 40gr) to replace the outer ring, and then 64 BCD to replace the inner ring? Then I would be able to run without the front derailleur?

BTW, what do the numbers mean, like 40G, 63G, 90G, etc? It looks like the larger numbers are larger in diameter, but what is the significance of that?

Finally, I can just unbolt the rings I don't want and install these "bash" rings, or do I have to remove the crank as well?

Thanks!

And btw, the main reason to remove some of the rear gears would be again, just for some romantic simplicity. There is something about having only the bare minimum I need to get me by. But, part of it is so I could space space the rear gearing away from the wheel some so the lowest two gears on the rear cassette are most directly in line with the front ring for the hard pulls. And then it would only have to go out of line by a couple more gears for the faster stuff. I'll probably wait at least a few more rides before I fully decide to go "1x," but it will be a good bit further down the road before I actually mess with the cassette if I wanted to go that route.

Wrong...you need an outer ring that's not a "trials" ring. Get one that's 32 or 34t.

40G, 63G, 90G: Weight in grams

You will need to remove the crankset to do the inner. It won't fit around the spider.

Regarding your spacing...this is why I suggested you move one of the 2.5mm bottom bracket spacers from the right to the left side. (assuming it's outboard) It would definitely work for ya...I've just never understood why someone would do something like that. It's not any more "romantically simple" to have a 5spd cassette than it is 9 or 10. You still have the same amount of control / derailleur / cable clutter. If you want simple...bag this idea and go singlespeed. You would be surprised at how much stronger you will be in just 2wks.

Thanks, ed! I have been doing a lot of reading on the subject and much better understand what needs to be done ("better" being the operative word ).

So, getting the 32t** bash ring, and the "64 BCD" that replaces the small ring, will provide the support I need to keep the chain in place? And, it would do a better job than the N-Gear JumpStop? I do also intend to have the chain shortened as well just to increase chain stability.

**Would getting a 34t provide a little more resiliance against outward chain-jumping? While I think I'd eventually get a single-speed front chainring for better chain retention, I don't see myself ever going up to a larger front ring than 32. So, if the only benefit of getting the larger bash ring would be protection for a larger chainring, then I will go with the 32t ring.

The "romantic simplicity" is entirely subjective, of course. While a 1x5 requires all the mechanics of a 1x9, there is something about having exactly what one needs and nothing more. But, I am a natural minimalist and do this in every part of my life (...until I moved earlier this year, I did all of my cutting in my kitchen with my pocket knife ).

For example, I just find this minimalist approach appealing (minimalist relative to ones needs--I still need some variability, just not all that much):

NGear Jump-stop is not terrible, but I rode with my Blackguard setup and my riding bud had the Jump Stop. His occasionally got stuck between the jump stop and the ring b/c it can flex outward enough while your pedaling forward to get past it. (it's not often mind you, but it happens)

A 32t is plenty. I beat the crap out of mine pretty hard and my 32t has kept my chain on. No reason to go with a 34t bash. Looks alot nicer IMO with a 32 as well. I'd say keep your OEM middle ring until you wear it out. A SS rampless ring won't gain you anything. A thick SS rampless ring will last longer than a thin ramped ring just b/c there's more material there. Not worth an immediate upgrade though.

I guess if you're willing to spend money to be more simple (and you find you only need like 3 gears)...consider a Hope Pro 2 singlespeed hub on your next wheel build. The singlespeed / trials freehub has enough room to fit 3 cogs, I believe. This will give you more dish and a stronger rear wheel.

My bike was 1x10 when I got it. I rode it that way for a while and managed to do most of the riding I wanted to around here. Then I started doing a bit more climbing and made it a 2x10. I have found the double to be of far more use. With a 36t in the back, I seldom have a need for a granny up front.

Hey ed thank you for all the advice! I just ordered the 104BCD 32t bash ring, and the 64BCD inner ring. I was thinking I would just go the PVC route if I decided to try reducing the number if gears on the rear. I also might look in to getting a larger rear sprocket to add to compensate for the loss of the granny front ring, just to get some more usability out of the cassette.

You could order the HG61 cassette and drop the bottom 4 off it. That'd give you a 36t low cog.

You have three options for a smaller middle ring too. There's an independent guy that builds 30t 104bcd rings for $90 a pop. You can also go to a website (I'll have to look it up) and order a 31t titanium 104bcd middle for somewhere around $90...or there's another company that machines rampless 31t 104bcd middle rings for $35. Color anodized and everything!

The difference between 31-30 is not worth spending $90 IMO, but running a 36t rear cog and a 31t middle ring would be really nice!

Aah thanks for the pointers! I probably won't bother with the 31t until mine is worn, but I might look into that HG61 you mentioned! Not a bad price and will provide about 5% more torque for longer climbs! With a 31t front that would be another 3% and would overall be closer to a 9% increase in available torque. If I went that would I would probably keep 6 gears on the rear.

Okay, I'm dumb. Not paying attention, I never actually stopped to think that my cassette is only an x8, so I'd be going 1x8 rather than 1x9 . Also, I was thinking it had a 34t large cog, but it is only 32. So, going with the HG61 would actually give me about a 12.5% increase in available torque while still giving me more speed than I need with the 12t small cog (which is still two gears lower than I've ever needed so far ).

BTW, would all nine cogs of the HG61 fit on my hub? Or would I have to remove one of the gears? Even with that and going to a 30t front, it would only take running one gear lower to get the same equivalent speed once I get a few cogs down into the cassette (basically 5th would = previous 4th, etc). So, I could still be very happy with the HG61 and even a 30t front I think, but if I went with that front I would probably keep all 8 rather than go down to ~6 gears. Not enough difference to justify the hassle, heh.

Okay, I'm dumb. Not paying attention, I never actually stopped to think that my cassette is only an x8, so I'd be going 1x8 rather than 1x9 . Also, I was thinking it had a 34t large cog, but it is only 32. So, going with the HG61 would actually give me about a 12.5% increase in available torque while still giving me more speed than I need with the 12t small cog (which is still two gears lower than I've ever needed so far ).

BTW, would all nine cogs of the HG61 fit on my hub? Or would I have to remove one of the gears? Even with that and going to a 30t front, it would only take running one gear lower to get the same equivalent speed once I get a few cogs down into the cassette (basically 5th would = previous 4th, etc). So, I could still be very happy with the HG61 and even a 30t front I think, but if I went with that front I would probably keep all 8 rather than go down to ~6 gears. Not enough difference to justify the hassle, heh.

8,9, and 10 speed cassettes can all be used on the same freehub (8, or 9 speed) body. I'm not certain about mountain bikes, but on road bikes, the 10 speed freehubs are different and won't work with an 8 or 9 speed cassette.

Cool. I might go ahead and order the HG61 then in the next few days. I rode at a new trail today and made it all the way through the "expert" section (woo!), but man was it tempting to pop it into the granny gear at some points! I never did, but on some of the longer uphills I was just dreaming about a lower cogset .

So again, just to clarify, I could buy the HG61, disassemble my current cassette for the spacers, and install 8 of the HG61 gears (the largest 8, most likely) on my hub with the original 8-speed spacers?

I was playing around with my bike's granny gear today and the difference between 3rd and 2nd in the rear (21 and 26t, respectively), is about the same ratio difference between the middle ring + 32t cog (lowest I have now), and the same 32t ring against a 39t cog. So, 22/21-->22/26 is roughly equal to 32/32 --> 32/39. This provides a pretty noticable decrease in pedal effort required for the roughs, and just for kicks I was able to climb up onto a 12" square railroad tie from a standstill with noticably greater ease.

I am not quite sure I am ready to drop $300 for the full Ti cassette, though I'd hate to spend $70 on the HG61 cassette and wish I'd gone a bit lower for $20 more (for a single cog). However, I'd want to make sure I could get away with just dropping one of the single 39t cogs into my cassette (removing the 11 or 12t cog in the process) without mechanical issues. I have read that my derailer should still work fine, but would there be any shifting or physical installatation issues just adding the 39t cog added to my cassette?

If not, I might also experiment with the "Mega Range" 34t cog I had on my old Raleigh. If it fits on my cassette without issues, I might just get a 30t front chainring from Anderson ( http://andersenmachine.wordpress.com/product-info/ ). I'd end up with the same low range with the 30/34 combo as I would adding a 36 to my current cassette and keeping the 30t chainring.

How well do you guys think each of these would work?

*edit*

And finally, am I currect in my understanding that I would still have to keep the 11t "first-position" cog?

In case anyone is wondering, I have received my HG61 and disassembled the cassette (ground out the rivets). When my cassette tool comes in tomorrow I will reassemble the rear wheel with the new cassette, probably with the 36-12 cogs minus the 14t one, but perhaps minus the 12t one if I can get it to work without the 12t bottom cog (with the 14t acting as the bottom). I am also going to order an Anderson 30t chainring with the 1x teeth configuration (no ramps and more robust tooth profile). I am preparing a write-up and will post more once I get them all installed. I can't go 1x until I get the chainring because the middle and inner rings are rivited together on my bike and I don't want to grind them off in case I decide to go back to stock. But, at least I was able to get the outer bash guard on there .

But yeah the lowest gear will offer about 20% more torque with the 30t chainring and 36t (up from 32t). I have experimented by climbing in the granny ring on the 26t rear cog, which has roughly the same ratio (22/26) as the 30/36 combo will. The 14t bottom cog and 30t chainring might be a little short in the long run--I have once go to a smaller cog than the current 4th, and that was to the 6th one very briefly. The 30/14 combo will be about like "5.5th" gear.

But, with the new cassette and chainring, I will basically have two gears below the three main ones I use now, those three will be stretched into roughly 3rd-7th of the new combo, and the smallest cog will be about like "6.5" gear, which is plenty.